/********************************************************************************
 * Copyright 2009 The Robotics Group, The Maersk Mc-Kinney Moller Institute,
 * Faculty of Engineering, University of Southern Denmark
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ********************************************************************************/

#ifndef RWSIM_UTIL_MOVINGAVERAGE_HPP_
#define RWSIM_UTIL_MOVINGAVERAGE_HPP_

#include <vector>

namespace rwsim { namespace util {

    /**
     * @brief
     */
    class MovingAverage
    {
      public:
        MovingAverage (int len) :
            _len (len), _invLen (1.0 / len), _cb (_len, 0.0), _sum (0.0), _idx (0)
        {}

        void addSample (double sample)
        {
            _sum -= _cb[_idx];
            _sum += sample;
            _cb[_idx] = sample;
            _idx++;
            if (_idx == _len)
                _idx = 0;
        }

        double getAverage () { return _sum * _invLen; }

      private:
        const int _len;
        double _invLen;
        std::vector< double > _cb;
        double _sum;
        int _idx;
    };
}}    // namespace rwsim::util

#endif /* MOVINGAVERAGE_HPP_ */
